Cardanic suspension device for a camera balance device

ABSTRACT

Disclosed is a cardiac suspension device ( 3 ) for a camera balance device ( 1 ), comprising two intersecting joint axes (G 1 , G 2 ); one of said axes extending vertically (G 2 ) (in a perpendicular manner) during operation and the other (G 1 ) extending horizontally, in addition to an axis rotation (D) extending through the vertical joint axis (G 2 ) and lying perpendicular to the horizontal joint axis (G 1 ). A joint output fixing element ( 27 ) can be rotated around verticalmjoint axis (G 2 ) and is used to fix the cardanic suspension device ( 3 ) on the camera balance device ( 1 ). A joint input fixing element ( 25 ) can rotate around the axis of rotation (D) and is used to fix the cardanic suspension ( 3 ) to a support. A centerin g device ( 43 ) is provided in the region of the vertical joint axis (G 2 ) and the horizontal joint axis (G 1 ), enabling the relative position between the joint output fixing element ( 27 ) and the camera balance device ( 1 ) to be established without slip in said region.

TECHNICAL FIELD

The present invention relates to a cardanic suspension device for acamera balance device according to the characterizing part of claim 1.

Camera balance devices of this kind are used to balance video and filmcameras which are guided manually by a camera operator and are connectedby means of a suspension device, for example, to a spring arm in awaistcoat-type carrying device (so-called body support) which is in turnattached to the body of the camera operator.

The suspension device is intended to prevent tilting and inclinedmovements, oscillations and stepping movements from the body of thecamera operator being transmitted to the camera because it is necessaryto guarantee a constant camera alignment at all times and avoid anytilting, inclination or oscillation of the camera. Alternatively, thecamera attached to the balance device may also be secured by means ofthe suspension device to a free-standing support, dolly, crane etc,whereby the suspension device is then able to prevent any unevenness ofthe ground exerting an influence on the position of the camera.

For this, the suspension device is designed so that the constructioncomprising camera and balance system is able to execute a pendulummotion relative to the support. In addition, this construction isconnected to counterweights. With a suitable choice and positioning ofthese counterweights, the camera is balanced in such a way that tiltingand inclination movements, oscillations and stepping movements are nottransmitted from the body support, free-standing support, dolly orcrane, etc. to the camera.

PRIOR ART

In a known camera balance device, the camera is attached to one end of apendulum arm to the other end of which the counterweights are fixed.Batteries are used, for example, as counterweights, which simultaneouslyfunction as energy stores.

The pendulum arm is connected to a cardanic suspension device which mayin turn be attached, for example, to a spring arm in a body support, toa support, dolly or crane.

In the cardanic suspension of the camera construction, three axes ofmotion are realized relative to the support: the suspension devicecomprises two intersecting joint axes (cardanic axes) one of said axesextending vertically (in a perpendicular manner) during operation andthe other extending horizontally, in addition to an axis of rotation,extending through the vertical joint axis and lying perpendicular to thehorizontal joint axis. A joint output fixing element can be rotatedabout the vertical joint axis and is used to fix the cardanic suspensiondevice to the pendulum arm of the camera balance device, and a jointinput fixing element, which may rotated about the axis of rotation, isused to fix the cardanic suspension device to a support, in particularto the aforementioned body support or also to a free-standing support.

U.S. Pat. No. 5,797,054 discloses a cardanic suspension for a camerabalance device according to the characterizing part of claim 1. However,here the clamp device for fixing the suspension device to the pendulumarm in the camera balance device is located in the area of the cardanicsuspension so that the clamping process can result in thedecentralization of the cardanic joint in relation to the three axes.

DESCRIPTION OF THE INVENTION

The object of the present invention is to provide an improved cardanicsuspension for a camera balance device with which the balance setting ismaintained over a wide range of camera movements and thedecentralization of the cardanic joint is avoided.

This object is achieved by a cardanic suspension device according toclaim 1. According to this, the output fixing element is fixed to thecamera balance device by means of a clamp device which is arranged insuch a way that the clamp device and the centering device are located atdistance from each other, preferably at opposite ends, on the jointoutput fixing element

The invention is based on the knowledge that the smallest deviations inthe centering of the cardanic suspension device relative to the pendulumarm exert a significant influence on the balance set by means of thecounterweights. Deviations in the centering of this kind can, forexample, be caused by tolerance deviations in the external diameter ofthe pendulum arm and result in substantial errors in the cameraguidance, in particular if this is performed at high speeds.

Therefore, it is particularly important that in the area of the cardanicjoint where the two joint axes and the axis of rotation meet there is noslip between the suspension device and the pendulum arm.

The centering according to the invention guarantees that that a balanceset by means of the counterweights is also retained, for example, if thecamera construction rotates about 360° relative to the support or thecamera operator with the suspension device moves through 360°. If thecentering is not performed precisely, even with rotations of less than180°, balance deviations occur in certain places, which in particularwith rapid movements, results in faulty camera guidance.

The fixing of the output fixing element to the camera balance device ispreferably achieved by means of a clamp device, which is arranged insuch a way that the clamp device and the centering device are located ata distance from each other and preferably at opposite ends of the jointoutput fixing element. The clamp device for fixing the suspension deviceto the pendulum arm in the camera balance device is then located as faraway as possible from the cardanic suspension so that the clampingprocess cannot not result in the decentralization of the cardanic jointrelative to the three axes.

Advantageous further developments of the cardanic suspension deviceaccording to the invention may be found in the dependent claims.

In one advantageous further development of the cardanic suspensiondevice according to the invention, the joint input and/or the jointoutput fixing element is formed as a handle. The joint input handles maybe used to attach the suspension device to a spring arm in the cameraoperator's waistcoat, to a support or similar. In addition, formanipulation, the joint output handle is also used for placing thesuspension device on the pendulum arm in the camera balance device.

The centering device can be adjustable, preferably steplesslyadjustable.

In an advantageous further development, the joint output fixing elementis formed as a straight tube. In this case, it is able to slide over thecorrespondingly formed pendulum arm in the camera balance device.Preferably, the suspension device is arranged movably on the camerabalance device or on the pendulum arm in order to change its positionrelative to the camera and counterweights.

The tube can, for example, have a circular section. Also conceivable isa rectangular or square embodiment.

In one advantageous embodiment, the centering device is formed by anadjusting ring provided with a clamping cone, which in turn interactswith a clamping ring. If the joint output fixing element is formed, asdescribed above, as a tube with a circular cross section, the adjustingring can be screwed into one end of the tube and interact with aclamping ring arranged on the camera balance device.

The clamping ring is preferably made of plastic. It can, however, alsobe made of metal, ceramic, a composite material or a combination ofthese materials. Preferably, there is at least one slot in the ring inorder to increase deformability and adaptability to the pendulum arm inthe camera balance device which extends therein.

The threaded ring is in turn preferably made of metal, but can, however,also be made of plastic, ceramic, a composite material or a combinationof these materials.

The suspension device according to the invention can also have a secondcentering device between the joint input and the joint output fixingelements, with which the vertical joint axis and the axis of rotationare able to move relative to each other. In this case, the centeringtakes place in a double manner: one centering device may be used toestablish the relative position between the joint output fixing elementand the camera balance device in the area of the two joint axes withoutslip. The second centering device may be used to move the vertical jointaxis and the axis of rotation relative to each other, preferably alongthe horizontal joint axis.

In an advantageous embodiment of the invention, the vertical joint axismay be moved along the axial extension of the horizontal joint axis bymeans of the second centering device. Here, the vertical joint axis maybe moved by means of at least one adjusting screw. A particularlypreferred embodiment has two adjusting screws whose longitudinal axesextend along the horizontal joint axis. However, it also conceivable toprovide only one adjusting screw and one spring-loaded thrust bearingopposite to this so that the adjustment is performed by turning thisadjusting screw.

SHORT DESCRIPTION OF THE DRAWINGS

The following describes the invention in more detail with reference toan example of an embodiment shown in the drawings.

These show:

FIG. 1 an overall view of a camera balance system and a cardanicsuspension device according to the invention,

FIG. 2 a detailed view of the cardanic suspension device according tothe invention

FIG. 3 a side view of the cardanic suspension device according to theinvention, partially in section, and

FIG. 4 a top view of the cardanic suspension device according to theinvention, partially in section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a camera balance device 1 together with a cardanicsuspension device according to the invention 3.

The camera balance device comprises a pendulum tube 5. At the upper endof the pendulum tube 5 there is a camera fixing device 7, whichsubstantially comprises a base 9 and a holding plate 11 to which acamera may be attached, whereby the holding plate 11 may be movedrelative to the base 9 by means of adjusting screws 13 (only one ofwhich is shown here) and to be precise into the plane of projectionshown in FIG. 1 or out of this plane. Other adjusting screws (not shown)are provided in order to move the holding plate 11 in FIG. 1 to theright and left relative to the base 9. At the lower end of the pendulumtube 5 there is a holding device 15 for counterweights. Provided in thisembodiment are a monitor holder 17 and two backing plates 19, 19″ tohold counterweights, which take the form of batteries, for example. Thebacking plate 19 is attached movably and fixably to sliding tubes 21 (ofwhich only one is visible) and may also be swiveled relative to thesliding tube 21; the backing plate 19 is locked in the desired angularposition by means of a clamping lever 23.

The construction comprising the pendulum tube 5, the camera holdingdevice 7 and the holding device 15 for counterweights is nowcardanically suspended in a suspension device 3 according to theinvention. This suspension device 3 is shown in more detail in FIGS. 2to 4 and comprises a first handle 25 as a joint input fixing element anda second handle 27 as a joint output fixing element. The first handle 25is used to attach the suspension device to a support, in particular to abody support worn by a camera operator. For this, the joint input handlehas a drill hole 26 by means of which it may be placed on a pivot on anupright stand or a spring arm in a waistcoat. The second handle 27 isused to attach the suspension device 3 to the camera balance device 1.For this, the second handle 27 has a tubular shape and is arrangedaround the pendulum tube 5 in the camera balance device 1 so that it maybe moved relative to the pendulum tube 5. The second handle 27 is lockedrelative to the pendulum tube 5 by means of a clamp device 29.

By means of the two handles 25, 27, a camera operator can guide withboth hands the construction fixed by means of the first handle 25 forexample to a spring arm, a body support, an upright stand, dolly orcrane.

Three axes of motion are realized in the joint connection between thefirst handle 25 and the second handle 27: the first handle 25 isconnected to a fork element 31 in such a way that it may be rotatedrelative to this fork element 31 about an axis of rotation Dcorresponding to the longitudinal axis of a straight section of thefirst handle 25 extending horizontally in FIG. 1. The fork element 31 isin turn connected swivelably about a horizontal joint axis G₁ (firstcardanic axis) to a joint outer ring 33. This joint outer ring 33 is inturn coupled rotatably about a vertical joint axis G₂ (second cardanicaxis) to a joint inner ring 35, which in turn is in a fixed connectionwith the second handle 27, which is attached by the clamp device 29 tothe pendulum tube 5 in the camera balance device 1. Hence, the firsthandle 25, which may be connected to the support, may be rotated inrelation to the second handle 27 connected to the pendulum tube 5 aboutthe axis of rotation D, swiveled about the horizontal joint axis G₁ andmounted rotatably about the vertical joint axis G₂.

The joint suspension device 3 is intended to prevent movements of thesupport, for example the body support, being transmitted to the cameraattached to the holding plate 11. For this, the construction comprisingthe pendulum tube 5, camera holding device 7 and counterweights must bepositioned on the holding device 15 with balance compensation. Toachieve this balance compensation in particular also for differentcamera types with different weights and different locations of thecenter of gravity, the camera balance device 1 has a plurality ofsetting options. In particular, the system balance is achieved by theprovision of counterweights of varying heaviness on the holding device15. As already mentioned above, the backing plate 19 for counterweightsis also mounted in a swivelable and movable way. The same may apply tothe monitor holding device 17. The embodiment shown has as the holdingdevice 15 for counterweights the monitor holder 17 and two backingplates 19, 19″; it is also obviously conceivable to provide other meansof attachment for counterweights at different points of the pendulumtube 5.

As also mentioned above, in addition the adjusting screws 13 may be usedto move the center of gravity of the camera (not shown) on the holdingplate 11 relative to the base 9 connected to the pendulum tube 5. Aneven more flexible system may be obtained if the pendulum tube 5 istelescopic.

The slightest deviations in the centering of cardanic suspension device3, or to be more precise of the joint inner ring 35, relative to thependulum tube 5 exert a significant influence on the balance set bymeans of the counterweights. Deviations in the centering of this kindcan, for example, be caused by tolerance deviations in the externaldiameter of the pendulum tube 5 and result in substantial errors in thecamera guidance, in particular when this is performed at high speeds.

For this reason, the suspension device according to the invention has onone side a centering device 37 with which the relative position betweenthe second handle 27 and the pendulum tube 5 may be established withoutslip. FIG. 3 elucidates this centering device 37, which is provided inthe area of the two intersecting joint axes G₁ and G₂. The centeringdevice 37 and the clamp device 29, which is used to fix the secondhandle 27 to the pendulum tube 5, are therefore located at opposite endsof the second handle 27. The distance between this clamp device 29 andthe centering device 37 prevents the clamping of the clamp device 29from having a detrimental impact on the centering device 37, i.e. fromcausing the decentralization of the suspension device 3 relative to thetwo joint axes G₁ and G₂ and the axis of rotation D.

The centering device 37 according to the invention has an adjusting ring39 provided with a thread which is screwed into the joint inner ring 35.In this embodiment, the centering device 37 is steplessly adjustable dueto the thread. This adjusting ring 39 has in its interior a cone whichpresses on a counter-cone in a slotted clamping ring 41 made of plastic,which is provided on the pendulum tube 5. The centering of the twoelements is therefore achieved by the interaction of the cone of theadjusting ring 39 with the cone of the clamping ring 41. The adjustingring 39 is preferably made of metal.

If the second handle 27 is pushed onto the pendulum tube 5 and said tubeis in the desired position, the handles 27 are fixed at a long distancefrom the joint axes G₁, G₂ by the clamp device 29, and the centering isperformed by the adjusting ring 39 and the clamping ring 41. This willprevent any slip, and in this position, reliable and good centering ofsuspension device 3 relative to the pendulum tube 5 is achieved. Inaddition, the suspension device 3 will also be fixed to the pendulumtube 5 at this point. However, the adjusting ring 39 and the clampingring 41 are primarily used for the centering and only subordinately forfixing.

In addition, in the arrangement according to the invention, both theclamp device 29 and the centering device 27 are easy to access.

The suspension device according to the invention 3 also has anothercentering device 43, which will now be described with reference to FIG.4. This other centering device 43 is used to move the vertical jointaxis G2 relative to axis of rotation D and in this way to center thependulum tube 5 in the camera balance device 1 relative to the forkelement 31 in the suspension device 3 according to the invention. In theembodiment shown, this centering device 43 is achieved by two adjustingscrews 47, which are screwed into the fork element 31 by means of veryfine threads and are also mounted swivelably relative to the joint outerring 33. In this way, these adjusting screws provide the connectionbetween the fork element 31 and the joint outer ring 33. The adjustingscrews 47 have entry holes 45 for a tool. Turning the adjusting screws47 achieves the centering of the fork element 31 relative to thependulum tube 5 by moving the threaded outer ring 33 and hence thevertical joint axis G₂ along the horizontal joint axis G₁ relative tothe fork element 31 and hence relative to the axis of rotation D. Here,the fine threads of the adjusting screws 47 permit adjustment in therange of hundredths of millimeters. In this way, the joint outer ring 33and hence the pendulum tube 5 can be arranged exactly centrally relativeto the fork element 31.

One of the two adjusting screws 47 can also be replaced by aspring-loaded thrust bearing.

The centering device 43 supplements the centering device 37 to achieve afurther improvement to the alignment of the suspension device 3according to the invention relative to the camera balance device 1.

1. Cardanic suspension device (3) for a camera balance device (1),comprising two intersecting joint axes (G₁, G₂) with one of said axes(G₂) extending vertically (in a perpendicular manner) during operationand the other (G₁) extending horizontally and with an axis of rotation(D) extending through the vertical joint axis (G₂) and lyingperpendicular to the horizontal joint axis (G₁), with a joint outputfixing element (27) that may be rotated about the vertical joint axis(G₂) to fix the cardanic suspension device (3) to the camera balancedevice (1), with said joint output fixing element (27) in the form of astraight tube being formed so that it may be fixed to a tube (5) in thecamera balance device and with a joint input fixing element (25) thatcan be rotated about the axis of rotation (D) to fix the cardanicsuspension (3) to a support, whereby a centering device (37) is providedin the area of the vertical joint axis (G₂) and the horizontal jointaxis (G₁) enables the relative position between the output fixingelement (27) and the camera balance device (1) to be established withoutslip in said region, characterized in that the fixing of the outputfixing element (27) to the camera balance device (1) is achieved bymeans of a clamping device (29) which is arranged in such a way that theclamp device (29) and the centering device (37) are located at adistance from each other, preferably at opposite ends, on the jointoutput fixing element (27).
 2. Cardanic suspension device (3) accordingto claim 1, characterized in that the joint input fixing element (25) isformed as a handle.
 3. Cardanic suspension device (3) according to claim1, characterized in that the joint output fixing element (27) is formedas a handle.
 4. Cardanic suspension device (3) according to claim 1,characterized in that the centering device (37) is formed to beadjustable.
 5. Cardanic suspension device (3) according to claim 4,characterized in that the centering device (37) is formed to besteplessly adjustable.
 6. Cardanic suspension device (3) according toclaim 1, characterized in that the tube has a circular cross section. 7.Cardanic suspension device (3) according to claim 1, characterized inthat the centering device (37) is formed by an adjusting ring (39) whichis provided with a clamping cone which in turn interacts with a clampingring (41).
 8. Cardanic suspension device (3) according to claim 1,characterized in that the centering device (37) is formed by anadjusting ring (39) which may be screwed into the end of the tube (27)and which is provided with a clamping cone which in turn interacts witha clamping ring (41) arranged on the camera balance device (1). 9.Cardanic suspension device (3) according to either claim 7,characterized in that the clamping ring (41) is made of plastic, metal,ceramic, a composite material or a combination of these materials. 10.Cardanic suspension device (3) according to claim 7, characterized inthat the there is at least one slot in the clamping ring (41). 11.Cardanic suspension device (3) according to claim 7, characterized inthat the adjusting ring (39) is made of metal, plastic, ceramic, acomposite material or a combination of these materials.
 12. Cardanicsuspension device (3) according to claim 1, characterized in that thesuspension device (3) is arranged movably on the camera balance device(1).
 13. Cardanic suspension device (3) according to claim 1,characterized in that between the joint input (25) and the joint outputfixing element (27) a second centering device (43) is provided withwhich the vertical joint axis (G₂) and the axis of rotation (D) are ableto move in relation to each other.
 14. Cardanic suspension device (3)according to claim 13, characterized in that the vertical joint axis(G₂) may be moved along the axial extension of the horizontal joint axis(G₁).
 15. Cardanic suspension device (3) according to claim 13,characterized in that the movement of the vertical joint axis (G₂) isachieved by means of at least one adjusting screw (47).
 16. Cardanicsuspension device (3) according to claim 15, characterized in that themovement of the vertical joint axis (G₂) is achieved by means of twoadjusting screws (47) whose longitudinal axes extend along thehorizontal joint axis (G₁),
 17. Cardanic suspension device (3) accordingto claim 2, characterized in that the joint output fixing element (27)is formed as a handle.
 18. Cardanic suspension device (3) according toclaim 8, characterized in that the clamping ring (41) is made ofplastic, metal, ceramic, a composite material or a combination of thesematerials.
 19. Cardanic suspension device (3) according to claim 14,characterized in that the movement of the vertical joint axis (G₂) isachieved by means of at least one adjusting screw (47).
 20. Cardanicsuspension device (3) according to claim 8, characterized in thatbetween the joint input (25) and the joint output fixing element (27) asecond centering device (43) is provided with which the vertical jointaxis (G₂) and the axis of rotation (D) are able to move in relation toeach other.